The Many Faces of Cholesterol: From its Role in Brain Function to its Impact on Cardiovascular Disease

Cholesterol is a sterol found in animals, specifically a zoosterol with the formula C17H28O. In fungi, a similar compound called ergosterol plays a role similar to cholesterol.

Drugs known as statins are used to lower cholesterol levels in the blood, which can reduce the risk of cardiovascular disease. These drugs work by inhibiting an enzyme involved in the 37-step process the human body uses to make cholesterol. Specifically, statins target the first 18 steps of this process.

Under certain conditions, such as when exposed to ultraviolet light, the body can convert cholesterol into calcitriol, an active form of vitamin D made in the kidneys.

The human body has a mechanism for recycling cholesterol that starts with its excretion from the liver and eventual reabsorption into the bloodstream in the small intestine. This process ensures that enough cholesterol is available for various functions in the body.

Cholesterol is also important for brain function because it can’t cross the blood-brain barrier on its own. Cells called astrocytes transport cholesterol across this barrier to support neuronal activity and maintain healthy brain function. Joseph Goldstein, an American biochemist who helped discover the role of cholesterol in heart disease and shared the Nobel Prize in Medicine in 1985 for this work, recognized its importance for brain health as well.